What Does Concrete Haunches Mean In Construction?
What Does Concrete Haunches Mean In Construction?
In construction, concrete haunches refer to the portion of material placed in an excavation on either side of and under a pipe from the top of the bedding up to the spring line or horizontal centerline.
Haunches are also used in masonry and brickwork to protect the end and angles from weathering.
In bridge construction, they are used to maintain a uniform deck thickness and account for camber and cross-slope.
Haunches can also be found in foundation walls, where they provide support for concrete porches or patios.
Finally, in constructing a pavement, concrete is piled up against the outer side of an edge course (haunched) to close to form a joint.
What Is The Purpose Of Haunching?
Haunching is the process of placing bedding material around the haunch of a pipe. It is used to provide structural support for pipes, such as drains and sewers, when there is no restraint from a wall or curb.
The weight of the pipe, water, and backfill compresses uncompacted bedding so that the pipe is effectively supported by the material around the haunch, reducing any concentrated load on the bottom of the pipe.
This helps to ensure that pipes are properly installed and can withstand external forces such as soil pressure or traffic loads.
How To Build Concrete Haunches?
Constructing concrete haunches requires a few steps.
- First, a foundation haunch assembly should be attached to the foundation wall. This can be done using a concrete block machine.
- Next, a preliminary BGS run should be executed using a beam framing option from 1-10 in the FOPT card.
- After that, the concrete slab on grade with haunch should be placed. The pier and abutment diaphragm concrete should also be placed.
- Finally, the concrete on which an edge course is bedded should be heaped up against the edge course’s outer side (haunched) to bring it near to the desired level.
How To Reinforce Concrete Haunches?
Reinforcement for concrete haunches is an important factor in the structural performance of a structure.
Haunches are used to support poured in place horizontal concrete slabs, stairs, stoops, pre-cast concrete slabs and similar structures.
Reinforced Concrete Beam Column Haunch Connection Detail is a CAD dwg drawing detail that provides full sizing and reinforcement detailing for designing haunched concrete beam-column connections.
The haunch provides additional cover for the reinforcement when doweling into existing reinforced concrete strips.
Guidelines for analyzing and designing haunches with different heights and reinforcement detailing have been developed by researchers.
Additionally, research has been conducted on the structural performance of haunch reinforced beams (RCHBs) which are used in construction of Portal frames, Bridges etc..
Why Is Haunch Provided In Retaining Walls?
Haunches are provided in retaining walls to increase the wall’s stability and strength. Haunch bars are used in the corners of tanks and other structures, such as retaining walls, to reduce the stress developed in the corner.
Haunch bars are also used to provide reinforcement for rectangular RCC box culverts. In addition, haunch bars can be used to provide a dry, hard surface for slabs on ground (SOGs).
Finally, haunch bars can be used to eliminate the need for a stem width of not less than 12 inches when constructing Type 1 retaining walls with safety barriers.
